Re: [PATCH net-next v3 1/3] netdevsim: Introduce support for L3 offload xstats

[Ido Schimmel <idosch@idosch.org>]

On Mon, Mar 14, 2022 at 03:01:15PM +0100, Petr Machata wrote:
> Add support for testing of HW stats support that was added recently, namely
> the L3 stats support. L3 stats are provided for devices for which the L3
> stats have been turned on, and that were enabled for netdevsim through a
> debugfs toggle:
> 
>     # echo $ifindex > /sys/kernel/debug/netdevsim/$DEV/hwstats/l3/enable_ifindex
> 
> For fully enabled netdevices, netdevsim counts 10pps of ingress traffic and
> 20pps of egress traffic. Similarly, L3 stats can be disabled for a given
> device, and netdevsim ceases pretending there is any HW traffic going on:
> 
>     # echo $ifindex > /sys/kernel/debug/netdevsim/$DEV/hwstats/l3/disable_ifindex
> 
> Besides this, there is a third toggle to mark a device for future failure:
> 
>     # echo $ifindex > /sys/kernel/debug/netdevsim/$DEV/hwstats/l3/fail_next_enable
> 
> A future request to enable L3 stats on such netdevice will be bounced by
> netdevsim:
> 
>     # ip -j l sh dev d | jq '.[].ifindex'
>     66
>     # echo 66 > /sys/kernel/debug/netdevsim/netdevsim10/hwstats/l3/enable_ifindex
>     # echo 66 > /sys/kernel/debug/netdevsim/netdevsim10/hwstats/l3/fail_next_enable
>     # ip stats set dev d l3_stats on
>     Error: netdevsim: Stats enablement set to fail.
> 
> Signed-off-by: Petr Machata <petrm@nvidia.com>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>